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UNITED STATES BATT FFICE.

JNO. R. MARSTON, OF NE'W YORK, N. Y.

DOOR-LOCK.

Specification of Letters Patent No. 20,571, dated June 15, 1858'.

To all whom it may concern:

Be it known that I, JOHN R. MARsToN, of the city, county, and State ofNew York, have invented a new and Improved Door- Lock; and I do herebydeclare the following to be a. full, clear, and exact descriptionthereof, reference being had to the accompanying drawings, figures andletters of reference thereon, and making part of this specification.

Of the said drawings Figure l, denotes an inside view of the lock theplate being removed for this purpose. Fig. 2, shows the plate turnedover from the lock and the mechanism attached to the said plate. Fig. 3,is a vertical section of Fig. l, taken through the line c, w. Fig. 4, isa vertical section of Fig. 2, taken through the line y.

Similar letters of reference indicate like parts in all the drawings.

The nature of my invention consists in the combination and arrangementof parts whereby I am enabled to make a lock proof against burglars fromthe outside when the door is locked on the inside, as will hereafter beset forth.

To enable others skilled in the art to make l and use my invention Iwill proceed to describe its construction and operation.

A A, represents the shell of the lock which is cast with the key hole l,and step 2 for the end of the key; and pieces projecting inward forsecuring the sliding bolt, latch and spring which are shown by iiguresand letters 5, 6, 7 and d, c, g.

B is the plate or cover to the lock which is shown in Fig. 2 as turnedover from the lock. This plate has pieces cast thereon for securingworking parts as shown by the letters o, p, g, and figure 8.

C is the bolt which is plainly shown in Fig. 1, having recesses ornotches cut at a, b, and 4, and also a stop at 3, and slides freelythrough the mortise and by means of the projecting pieces on the lockplate.

D is the catch bolt passing through a mortise in the shell of the lockand attached to the lever E, which lever is operated by t-he tumbler F,on the shaft Gr. The tumbler F has a square hole cast through it whichis fitted by the shaft G, which passes through the lock plate (and isheld in place by the collar 2,) to each end of which is fitted the knob.The upper end of the lever E, is secured to the pin (Z, which is thefulcrum while a point of it (back of the center of vibration,) restsupon the spring f at Z, which spring serves to drive the catch outwardwhen released from pressure in opening the door.

H is the catch bar which serves to secure the bolt in place when thedoor is locked or unlocked and has its fulcra at c, and has ears castthereon as plainly shown in Figs. l and 3. The spring f serves thepurpose of operating both the catch bar H and tumbler lever E, andreceives its tension from the projecting piece cast on the lock plate atg, in Fig. l.

The sliding plate I which covers the outside keyhole is shown in Figs. 2and 4, and is cast with a projecting piece 2f, and a semicircular piececut out as seen at u, and also has a slot cast at g, which in connectionwith the projections 0, p, s, and 8 serve as sliding bearings for theplate. This slide has recesses c, and r r, which in combination with thebar J, serve to securely cover and protect the outside keyhole whenlocked from the inside-the sliding bar J being kept in place by means ofthe spring z', which rests upon the catch bar at n, the spring beingsecured at j, and having its fulcrum at 7c, as plainly seen in Fig. 3.

Operation: The key being inserted to lock the door from the inside, oneend of it will rest in the step l, Fig. l, which with the hole in thelock plate will form a good bearing for the key and as it is turned willsimultaneously raise the catch bars H, and J, by passing under theirinclined surfaces which releases both the sliding bolt C, and key holeplate I, and as the key revolves catches into the notches a, and c, andforces the bolt and slide plate over the key hole (outside) at the sameinstant, when the springs f and z' force the catch bars into the notchesr, on the plate I and front of 3, on the bolt H.

The door is locked from the outside by the key being passed through thehole 2, and in the step 2, and as it is turned will catch into therecess b, after having raised the bar H, so as to release it from thebolt C, and force it forward when the spring f, forces by its pressureat m, the catch bar into the recess at 3, in the bolt C.

It will readily be seen that the key holes from the inside and outsidehave no communication with each other, neither passing through the door,hence no jimmies or other burglars tools would be available and adsovditional security and protection guaranteed from entrance by the use ofthis lock.

I do not claim separately7 any of the parts as they are Well known. I amaware of the 5 patent of Wm. Moore Sept. 14:, 1852, and I therefore makeno claim to any device patented to him; but

I claim- The sliding key hole cover I, constructed 10 and operatingsubstantially as described,

and acting in combination With the bolt C, for the purpose of making adoor lock proof against any outside communication when locked from theinside, Without requiring any adjustment substantially as set forth 15and specified.

JOHN R. MARSTON. [1.. s.] IVitnesses:

Gmo. W. Loon,

C. A. DURGEN.

